Forty million people around the world now live with HIV/AIDS, the majority in sub-Saharan Africa. In the East African countries of Kenya, Tanzania and Uganda alone, nearly seven million men, women and children are infected with HIV. Despite the fact that the developing world is the epicenter of the HIV/AIDS pandemic, most research initiatives and treatment guidelines have been developed using patient populations from resource-rich areas. While important clinical protocols and treatment guidelines have emerged from these research initiatives they may not successfully transfer to the vast majority of HIV/AIDS patients who live in resource-poor areas. As an example, while most clinical protocols have been developed among populations infected with HIV-1 subtype B, the predominant strain in the developed world, in sub-Saharan Africa, in general, and East Africa, in particular, a variety of HIV-1 non-B subtypes are found. This fact may have far- reaching implications for critical aspects of antiretroviral treatment, including the timing of initiation of antiretroviral therapy and development of resistance to first-line regimens. Also, due to poverty, malnutrition and the existence of various infectious diseases not commonly encountered in more resource-rich parts of the world, such as malaria, tuberculosis, and waterborne pathogens, treatment and care of HIV-infected patients in sub-Saharan Africa is uniquely complex as compared to more prosperous regions of the globe. Indiana University, with partners at the University of California San Francisco, Columbia University, Yale University, Moi University in Kenya and Mbarara University in Uganda and support from the World Health Organization and various agencies and private foundations, have established a number of extensive HIV/AIDS treatment and research networks in the East African nations of Kenya, Uganda, and Tanzania. With this application we aim to create a regional Data Center for East Africa as part of the IEDEA Consortium. This Center will not only merge and share data among current and future partners, but also offer unparalleled research capacity to identify and address questions that are amendable to combined regional database analysis. Our East Africa Regional IEDEA Consortium will fulfill the following functions: 1) Identify data from existing HIV/AIDS care and research networks in the East Africa region;2) Develop protocols to harmonize and merge data and provide training and education to accomplish this task;3) Share data within the East Africa Regional Consortium, the worldwide IEDEA Consortium, and collaborating investigators from the broader scientific community;4) Identify and pursue critical questions related to HIV/AIDS care, treatment and research that can be addressed with combined regional data. Particular emphasis will be placed on HIV-related questions that have broad applicability across regions and populations.